JP2016080970A - Position detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position detector that can conduct closed-loop control in an auto-focus mode, reduce influence of a leakage magnetic field, and exhibit an excellent linearity.SOLUTION: A first auto-focus coil 43a and a second auto-focus coil 43b are wound around an optical axis direction a. A part or all of magnets 41a to 41d are arranged near the coils 43a and 43b to be separated from each other in a planer view perpendicular to the optical axis direction a. The magnetic sensor 42a has a magnetism-detecting axis parallel to the optical direction a detecting the magnetic fields of the magnets 41a to 41d. A supporting unit supports the magnetic sensor 42a and the first and second auto-focus coils so that the magnetic sensor is arranged in a region with the width of the conductor of the first auto-focus coil 43a which is along the optical axis direction a.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a position detection apparatus, and more particularly to a position detection apparatus that can perform closed-loop control in autofocus, can reduce the influence of a leakage magnetic field, and has good linearity.

  In recent years, digital video cameras, digital still cameras, single-lens reflex cameras, and the like have been improved in performance and image quality, and accordingly, performance requirements for the photographic lens unit are also increasing. In particular, in order to increase the speed of autofocus (AF) and zoom, and to increase the accuracy of AF and zoom lens position detection, a moving lens group such as an AF and zoom lens is driven by a magnet and a coil. Actuators have come to be used. For detecting the position of the moving lens group, a position detection method in which a Hall sensor or MR sensor (magnetoresistance effect element), which is a magnetic sensor, and a magnet are combined is known.

In recent years, opportunities for taking still images using a small camera for a mobile phone are increasing. Along with this, not only the AF function, but also a camera shake correction function that enables clear shooting by preventing image blur on the imaging surface even if there is camera shake (vibration) when shooting a still image. Various devices have been proposed.
In a camera device mounted on this type of mobile phone, in order to reduce the size and cost, the camera lens driving method is not closed loop control, and control that does not feed back the lens position to the lens position control unit ( It is normal to use open loop control.

For example, the device described in Patent Document 1 relates to a lens driving device that can correct a camera shake (vibration) that occurs when a still image is captured with a small camera for a mobile phone so that an image without image blur can be captured. In addition, it is disclosed that the Hall element, which is a position detection sensor, can be prevented from being adversely affected by a magnetic field generated by a current passed through a coil.
Further, for example, the one described in Patent Document 2 relates to a lens actuator that realizes miniaturization while maintaining drive performance, and a moving lens having a lens and a coil wound around the optical axis of the lens. And a plurality of magnets arranged around the optical axis along the outer surface of the moving lens body.

  Further, for example, the one described in Patent Document 3 achieves an autofocus mechanism and a camera shake correction mechanism using closed loop control, and an autofocus mechanism for moving along the optical axis of the lens; BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detection device having a camera shake correction mechanism for moving in a direction orthogonal to an axis, and a camera shake correction in which a permanent magnet for autofocus used in the autofocus mechanism is used in the camera shake correction mechanism. A permanent magnet shared with the permanent magnet, an autofocus coil provided in the vicinity of the permanent magnet, a first position sensor for detecting the position of a lens driven by the autofocus coil, and a permanent magnet A camera shake correction coil provided in the vicinity and a second position sensor for detecting the position of the lens driven by the camera shake correction coil. And it has a door.

JP 2013-024938 A JP 2010-224489 A International Publication No. 2013/183270

However, Patent Documents 1 and 2 described above do not have a magnetic sensor for detecting the position of the lens moving in the optical axis direction (autofocus), and the magnetic sensor determines the positional relationship between the magnet and the autofocus coil. Closed loop control that detects and drives the autofocus coil is not performed.
In Patent Document 3 described above, closed loop control is performed, but still a position detection error occurs when the magnetic sensor detects a magnetic field (leakage magnetic field) generated from the autofocus coil. Further, the linearity of the output voltage of the magnetic sensor with respect to the movement distance in the optical axis direction was also insufficient.
The present invention has been made in view of such a problem. The object of the present invention is to enable closed-loop control in autofocus, to reduce the influence of a leakage magnetic field, and to have good linearity. The object is to provide a position detection device.

The present invention has been made to achieve such an object, and has the following features.
(1); In a position detection apparatus having an autofocus mechanism for moving an optical element along the optical axis direction, a first autofocus coil wound around the optical axis direction, and the optical axis direction A magnet that is spaced apart from the periphery of the first autofocus coil in a vertical plan view, and a magnetic sensor that senses the magnetic field of the magnet with a magnetosensitive axis parallel to the optical axis direction; The first autofocus coil and the magnetic sensor are supported so that the magnetic sensor is disposed in a region along the optical axis direction of the conductor width of the conductor portion forming the first autofocus coil. And a support part.

(2); In (1), the support unit includes the magnetic sensor and the first sensor so that a magnetosensitive axis of the magnetic sensor is close to a central axis along the optical axis direction in the conductor width of the conductor portion. 1 autofocus coil is supported.
(3); In (1) or (2), the first autofocus coil and the second autofocus coil are further arranged in parallel to the first autofocus coil with respect to the optical axis direction. And the magnetic sensor is disposed between the first autofocus coil and the second autofocus coil.

(4) In any one of (1) to (3), the magnetizing direction of the magnet is a direction perpendicular to the optical axis direction, and the magnets are connected to the first and second autofocus coils. It is characterized by being magnetized in the surface direction.
(5) In any one of (1) to (4), the magnetic sensor is sandwiched between the first autofocus coil and the second autofocus coil, and with respect to the magnetization direction of the magnet. It is arranged at the center position in the vertical longitudinal direction and the short direction.

(6); In any one of (1) to (4), the magnetic sensor is sandwiched between the first autofocus coil and the second autofocus coil, and with respect to the magnetizing direction of the magnet. It is arranged at a position deviating from the center position in the vertical longitudinal direction and the short direction.
(7); In any one of (1) to (5), a plurality of the magnets are arranged along the periphery of the first autofocus coil and the second autofocus coil. To do.

(8); In (7), the magnetic sensor is sandwiched between the first autofocus coil and the second autofocus coil, and is disposed between the adjacent magnets. .
(9); In (7) or (8), the first autofocus coil and the second autofocus coil are arranged inside the plurality of magnets.
(10); In (7) or (8), the first autofocus coil and the second autofocus coil are arranged outside the plurality of magnets.

(11) In any one of (1) to (10), the first autofocus coil and the second autofocus coil have the same shape.
(12) In (11), the first autofocus coil and the second autofocus coil are square coils, and the magnetic sensor is disposed between four corners of the square coil. It is characterized by being.

(13) In any one of (1) to (12), closed loop control is used for the autofocus mechanism, and the optical element is controlled based on position information from the magnetic sensor of the autofocus mechanism. Features.
(14) In any one of (1) to (13), the magnetic sensor is a Hall element.

  According to the present invention, it is possible to realize a position detection apparatus that can perform closed-loop control in autofocus, can reduce the influence of a leakage magnetic field, and has good linearity.

(A) thru | or (c) are the block diagrams for demonstrating Embodiment 1 of the position detection apparatus which concerns on this invention. (A) thru | or (c) are the block diagrams for demonstrating Embodiment 2 of the position detection apparatus which concerns on this invention. (A) thru | or (c) are the block diagrams for demonstrating Embodiment 3 of the position detection apparatus which concerns on this invention. It is a block diagram for demonstrating Example 1 of the position detection apparatus which concerns on this invention. FIG. 5 is a top view of the position detection apparatus according to the first embodiment illustrated in FIG. 4. It is a block diagram for demonstrating Example 2 of the position detection apparatus which concerns on this invention. FIG. 7 is a top view of the position detection apparatus according to the second embodiment illustrated in FIG. 6. (A) And (b) is a block diagram for demonstrating the specific example 1 as Example 2 shown in FIG. (A) thru | or (d) are the block diagrams provided with the camera-shake correction function in the specific example 1 shown to Fig.8 (a). It is a block diagram for demonstrating Example 3 of the position detection apparatus which concerns on this invention. FIG. 11 is a top view of the position detection apparatus according to the third embodiment illustrated in FIG. 10. It is a block diagram for demonstrating Example 4 of the position detection apparatus which concerns on this invention. It is a top view of the position detection apparatus according to the fourth embodiment shown in FIG. (A) And (b) is a block diagram for demonstrating the specific example 2 as Example 4 shown in FIG. (A) thru | or (d) are the block diagrams provided with the camera-shake correction function in the specific example 2 shown to Fig.14 (a). (A) And (b) is a block diagram which shows the arrangement | positioning relationship of the magnet shown by patent document 3, the coil for Z-axis AF, and the sensor for Z-axis AF. (A) thru | or (d) is a figure which shows the arrangement | positioning relationship and linearity of the magnet and sensor for Z-axis AF in the past and this embodiment.

Hereinafter, each embodiment of the present invention will be described with reference to the drawings.
<Embodiment 1>
FIGS. 1A to 1C are configuration diagrams for explaining Embodiment 1 of the position detecting device according to the present invention, FIG. 1A is an overall perspective view, and FIG. 1B is a front view. FIG. 1C is a characteristic diagram of the output voltage at the position of the magnetic sensor in the Z-axis direction. Note that arrows with the autofocus coils 13a and 13b indicate the current direction (current line).

  In the position detection device shown in FIGS. 1A and 1B, a linear portion is arranged along the longitudinal direction (Y-axis direction) of the magnet 11 with respect to the magnet 11 magnetized in the X-axis direction. The first autofocus coil 13a, the second autofocus coil 13b arranged in parallel to the first autofocus coil 13a and in the short direction (Z-axis direction) of the magnet 11, The magnetic sensor 12 is provided between the autofocus coil 13a and the second autofocus coil 13b and disposed at the center in the longitudinal direction and the short direction of the magnet 11.

  In the case of the arrangement described above, the magnetic sensor 12 outputs a voltage proportional to the Z-axis direction component of the magnetic flux density applied to the magnetic sensor 12. The magnetic sensor 12 moves with the autofocus coils 13a and 13b along the Z-axis direction with respect to the fixed magnet 11. At this time, since the amount of change in the output voltage of the magnetic sensor 12 that changes with movement has a high linearity with respect to the amount of movement, the position can be detected with high accuracy by monitoring the amount of change in voltage. The magnet 11 may move along the Z-axis direction with respect to the fixed magnetic sensor 12.

Since the magnetic sensor 12 and the first and second autofocus coils 13a and 13b are supported by a support portion (not shown) (reference numeral 44 in FIG. 8B), the first and second autofocus coils 13a and 13b are supported. The magnetic sensor 12 also moves with the focus coils 13a and 13b.
The magnetic sensor 12 outputs a voltage proportional to the Z-axis direction component of the magnetic flux density applied to the magnetic sensor 12. In addition, the magnetic sensor 12 is disposed in a region along the optical axis direction of the conductor width of the conductor portion forming the first and second autofocus coils 13a and 13b on the X axis. In the conductor width, it is preferable that the center axis b along the optical axis direction and the center of the magnetic sensitive axis of the magnetic sensor 12 are substantially aligned. In FIG. 1, the above-described region is a projected region along the optical axis direction of the conductor portion that forms the autofocus coil 13a or 13b. The magnetic sensor for detecting the magnetic field is arranged so as to be within the projection area.

In the first embodiment, it is arranged so that at least a part of the magnetically sensitive part of the magnetic sensor 12 overlaps the conductor width d of the conductor part of the autofocus coil when viewed from above.
Within the above-mentioned range, it is preferable that the center of the magnetically sensitive portion of the magnetic sensor 12 is arranged so as to overlap when viewed from above.
More preferably, the arrangement is such that the center axis in the width direction of the conductor width d of the conductor portion of the autofocus coil and the center of the magnetically sensitive portion of the magnetic sensor 12 coincide in the optical axis direction.

For example, in the case of a magnetic sensor in which a compound Hall element is packaged with a sealing resin, a configuration in which the compound Hall element portion is disposed so as to be within the above-described conductor width d is preferable. The sealing resin portion, the lead frame portion, and the like may be within the above range or outside the range.
In addition, in the case of a magnetic sensor in which a silicon-based Hall element and a semiconductor integrated circuit are integrated into one chip, a configuration in which the silicon-based Hall element is arranged so as to be within the above-described conductor width d is preferable. The semiconductor integrated circuit portion or the like may be within the above range or outside the range.
Note that even if the center is slightly deviated due to design or assembly error, a large magnetic flux density is not immediately applied, and how much it can be deviated is considered in the implementation stage.

Further, linear portions of the first and second autofocus coils 13a and 13b in which current flows in the Y-axis direction are arranged above and below the Z-axis of the magnetic sensor 12. The magnetic fields generated by the first and second autofocus coils 13 a and 13 b do not interfere with the magnetic sensor 12.
Most of the magnetic field components received by the first and second autofocus coils 13a and 13b from the magnet 11 are X-axis components, thereby generating a large Lorentz force in the Z-axis direction. On the other hand, the magnetic field components received by the first and second autofocus coils 13a and 13b from the magnet 11 include some Z-axis components. As a result, the Lorentz force of the X-axis component also slightly occurs. The Lorentz force of the X-axis component is a force that rotates the first and second autofocus coils 13a and 13b around the Y-axis. Since this is an unintended movement, a module in which the first and second autofocus coils 13a and 13b and the magnetic sensor 12 are integrated so that the first and second autofocus coils 13a and 13b do not rotate is as follows. A guide bar (not shown in FIG. 8B) (not shown) that operates only in the Z-axis may be provided.

By using a mechanism in which the first and second autofocus coils 13a and 13b and the magnetic sensor 12 move in conjunction with each other, the following operation is performed.
1) A coil current is passed through the first and second autofocus coils 13a and 13b.
2) Lorentz force mainly in the Z-axis direction is generated in the first and second autofocus coils 13a and 13b.
3) The first and second autofocus coils 13a, 13b and the magnetic sensor 12 move on the Z axis in conjunction with each other.
4) The amount of current flowing through the autofocus coils 13a, 13b is controlled by the magnetic sensor 12 detecting the amount of movement (closed loop). Coil magnetic field interference at this time can be ignored.
The same applies to a mechanism in which only the magnet 11 moves.

Here, the comparison with the conventional patent document 3 is performed.
16 (a) and 16 (b) are configuration diagrams showing the positional relationship among the magnet, the Z-axis AF coil, and the Z-axis AF sensor disclosed in Patent Document 3, and FIG. 16 (a) is a perspective view. 16 (b) shows a top view.
As shown in FIGS. 16A and 16B, in Patent Document 3 described above, a Z-axis AF sensor 64Z is disposed in the vicinity of the two Z-axis AF coils 63Z and 63Z. By passing a current through the Z-axis AF coils 63Z and 63Z, a thrust in the Z-axis direction is generated in the magnet 62, and the output of the Z-axis AF sensor 64Z that changes according to the movement of the magnet 62 is monitored. The position of the direction magnet 62 can be detected. However, the magnetic field generated by the Z-axis AF coil with respect to the Z-axis AF sensor has a component of the magneto-sensitive axis direction of the Z-axis AF sensor 64Z and is detected. As a result, a position detection error is caused.

On the other hand, in the present embodiment, the magnetic field from the AF coil hardly affects the magnetic sensor due to structural features.
FIGS. 17A to 17D are views showing the arrangement relationship and linearity between the conventional magnet and the Z-axis AF sensor in this embodiment, and FIG. 17A shows the conventional magnet and the Z-axis AF sensor. 17 (b) is a characteristic diagram showing the linearity in FIG. 17 (a), FIG. 17 (b) is an arrangement of the magnet and the Z-axis AF sensor of this embodiment, and FIG. 17 (d) is FIG. 17 (b). It is a characteristic view which shows the linearity in).

  As shown in FIGS. 17A and 17C, in the conventional configuration, the applied magnetic field to the Z-axis AF sensor 64Z, which fluctuates with the movement of the magnet 62 in the Z-axis direction, depends on the movement amount of the magnet 62. On the other hand, a curve is drawn, and it cannot be said that it has high linearity. On the other hand, the linearity obtained in this embodiment has a very high linearity as shown in FIGS. 17B and 17D. Of course, the same result can be obtained even if the sensor moves in the Z-axis direction.

<Embodiment 2>
2 (a) to 2 (c) are configuration diagrams for explaining Embodiment 2 of the position detecting device according to the present invention, FIG. 2 (a) is an overall perspective view, and FIG. 2 (b) is a front view. FIG. 2C is a characteristic diagram of the output voltage at the position of the magnetic sensor in the Z-axis direction. In FIG. 1A, two current lines are shown above and below the autofocus coil. However, as shown in FIG. 2A, only one current line may be used. In this case, the thrust is weaker than in the case of FIG.
The magnetic sensor 22 is disposed around the autofocus coil 23, that is, on the X axis so that the center axis b in the width direction of the autofocus coil 23 and the center of the magnetosensitive axis of the magnetic sensor 22 substantially coincide with each other, and the magnet 21. It is located at the center in the longitudinal direction and the transverse direction perpendicular to the magnetization direction of

<Embodiment 3>
3A to 3C are configuration diagrams for explaining Embodiment 3 of the position detection apparatus according to the present invention. FIG. 3A is an overall perspective view and FIG. 3B is a front view. FIG. 3C is a characteristic diagram of the output voltage at the position of the magnetic sensor in the Z-axis direction.
The position of Stroke = 0 of the magnetic sensor 32 may not necessarily coincide with the center in the longitudinal direction and the short direction perpendicular to the magnetization direction of the magnet 31. However, since the region where the linearity of the output is low is used, the position detection accuracy (linearity) is better in the configuration of FIG. 1 (a) or FIG. 2 (a).

FIG. 4 is a configuration diagram for explaining the first embodiment of the position detecting device according to the present invention, and FIG. 5 is a top view of the position detecting device according to the first embodiment shown in FIG.
The position detection apparatus according to the first embodiment is a position detection apparatus having an autofocus mechanism for moving a lens (not shown) as an optical element along the optical axis direction a.
The first and second autofocus coils 43a and 43b are wound around the optical axis direction a. The central axis direction of the coil is provided in parallel with the optical axis direction a.

In addition, any or all of the magnets 41a to 41d are arranged apart from the periphery of the first and second autofocus coils 43a and 43b in a plan view perpendicular to the optical axis direction a. That is, in FIG. 4, a plurality of magnets 41a to 41d are arranged along the outer periphery of the first autofocus coil 43a and the second autofocus coil 43b.
In addition, the magnetosensitive axis of the magnetic sensor 42a is parallel to the optical axis direction a and detects the magnetic fields of the magnets 41a to 41d. Further, the magnetic sensor 42a is arranged so that its magnetic sensitive axis is close to the central axis b in the conductor width d of the current lines of the first and second autofocus coils 43a and 43b.

Further, a support (not shown) (reference numeral 44 in FIG. 8B) is arranged at a position along the optical axis direction a of the first and second autofocus coils 43a and 43b with the first and second magnetic sensors 42a. The second autofocus coils 43a and 43b are supported.
The first and second autofocus coils 43a and 43b are preferably arranged in parallel along the optical axis direction a and have the same shape.

Further, the magnetic sensor 42a has a periphery along the central axis b in the conductor width d of the first autofocus coil 43a and the second autofocus coil 43b, that is, the first autofocus coil 43a and the second autofocus. It arrange | positions in the position pinched | interposed into the coil 43b.
In addition, the magnetization direction of any or all of the magnets 41a to 41d is perpendicular to the optical axis direction a and the radial directions of the first and second autofocus coils 43a and 43b from the magnets 41a to 41d ( It is magnetized in the case of a circular coil) or in the surface direction (in the case of a circular coil and a square coil on a flat plate).

Further, the first autofocus coil 43a and the second autofocus coil 43b are square coils, and the magnetic sensor 42a is disposed between the center positions of either side of the square coil. Note that the cross-sectional shape of the autofocus coil may be any of a circle, an ellipse, and a rectangle.
Further, the magnetic sensor 42a is sandwiched between the first autofocus coil 43a and the second autofocus coil 43b, and at the center position in the longitudinal direction and the short direction perpendicular to the magnetization direction of the magnets 41a to 41d. Has been placed. The magnetic sensor is preferably a Hall element.

With the configuration described above, interference from the autofocus coil to the magnetic sensor can be reduced, and the positions of the autofocus coil and the magnetic sensor on the Z-axis can be detected with high accuracy.
In general, the closed AF has a large number of parts (such as an AF detection magnet and a detection sensor), and has a structure that also serves as an OIS (Optical Image Stabilizer) magnet. There is an advantage that the change and the increase in the number of parts are small.

In addition, since the autofocus coil and the magnetic sensor are supported by the support portion, the magnetic sensor also moves along with the autofocus coil, and the relative position of the magnet and the magnetic sensor changes. By detecting the position, the position can be detected, thereby enabling closed loop control.
In addition, since the magnetic field generated from the autofocus coil is parallel to the magnetic sensing direction with respect to the magnetic sensor, the magnetic sensor is not easily affected by the leakage magnetic field. Furthermore, linearity is improved by using a magnetic sensor in which the magnetosensitive direction is the optical axis direction with respect to the magnet.

6 is a block diagram for explaining a second embodiment of the position detection apparatus according to the present invention, and FIG. 7 is a top view of the position detection apparatus according to the second embodiment shown in FIG. In addition, the same code | symbol is attached | subjected to the component which has the same function as FIG.
The magnetic sensor 42b is sandwiched between the first autofocus coil 43a and the second autofocus coil 43b and deviates from the center position in the longitudinal direction and the short direction perpendicular to the magnetizing directions of the magnets 41a to 41d. Placed in position.
Further, the first autofocus coil 43a and the second autofocus coil 43b are square coils, and the magnetic sensor 42b is disposed between four corners of the square coil.

  Thus, the position condition of the magnetic sensor may be any position as long as the magnetic field of the autofocus coil is parallel to the surface of the magnetic sensor and the necessary linearity can be secured. For example, the magnetic sensor does not necessarily have to be arranged at the center of the magnet as shown in FIG. 4, and high linearity can be secured even at a position between two adjacent magnets as shown in FIG.

<Specific example 1>
FIGS. 8A and 8B are configuration diagrams for explaining a specific example 1 as the second embodiment shown in FIG. 6, and FIG. 8A is a diagram for a magnet, an autofocus coil, a magnetic sensor, and an OIS. FIG. 8B is a perspective view in which a guide bar, an autofocus coil holding mechanism, and a mounting board are attached. In addition, the same code | symbol is attached | subjected to the component which has the same function as FIG.
That is, FIG. 8A is a diagram in which elements unnecessary for the magnetic circuit such as the substrate, the holding mechanism, and the guide bar are deleted from FIG. 8B.

  As shown in FIG. 6, the magnetic sensor 42b is sandwiched between the first autofocus coil 43a and the second autofocus coil 43b and has a longitudinal direction perpendicular to the magnetization direction of the magnets 41a to 41d and It is arranged at a position deviating from the center position in the short direction. That is, the magnetic sensor 42b is sandwiched between the first autofocus coil 43a and the second autofocus coil 43b, and is disposed between the adjacent magnets 41c and 41b. The magnetic sensor 42b may be disposed between the magnets 41d and 41a, 41a and 41c, and 41b and 41d.

Further, the support 44 as a lens holder has a magnetic sensor 42b and the first and second autofocus coils 43a at positions along the optical axis direction a of the first and second autofocus coils 43a and 43b. , 43b.
Further, the camera shake correction coil 45 is provided on a flexible printed circuit board (FPCB) 48 and is arranged corresponding to each of the magnets 41a to 41d.

The guide bar 46 is a module in which the first and second autofocus coils 43a and 43b and the magnetic sensor 42b are integrated so that the first and second autofocus coils 43a and 43b do not rotate. It is provided to operate only on the shaft.
The camera shake correction drive unit support 47 is provided between the camera shake correction coil 45 and each of the magnets 41a to 41d in correspondence with the flexible printed circuit board (FPCB) 48.
With such a configuration, it is useful to arrange the magnetic sensor at the corner of the actuator in order to reduce the actuator size.

FIGS. 9A to 9D are configuration diagrams provided with the camera shake correction function in the specific example 1 shown in FIG. 8A, and FIG. 9A is the same perspective view as FIG. 9B is a top view of FIG. 9A, FIG. 9C is a side view of FIG. 9B, and FIG. 9D is a side view of FIG. 9B. In the figure, reference numeral 49X denotes a camera shake correction magnetic sensor (X-axis detection), and 49Y denotes a camera shake correction magnetic sensor (Y-axis detection).
That is, FIG. 9A is a diagram in which elements unnecessary for the magnetic circuit such as the substrate, the holding mechanism, and the guide bar are deleted from FIG. 8B.

A camera shake correction coil 45 provided in the vicinity of the magnets 41a to 41d, a camera shake correction magnetic sensor (X-axis detection) 49X and a camera shake correction magnetic sensor (Y) fixed to the same substrate as the camera shake correction coil 45. Axis detection) 49Y.
Further, the axial direction of the camera shake correction coil 45 is arranged to be parallel to the optical axis direction a. By energizing the camera shake correction coil 45, the guide bar 46, magnets 41a to 41d supported by the camera shake correction drive unit support section 47, and the support section 44 as a lens holder are driven in the X axis and the Y axis. Further, the closed loop control is used for the autofocus mechanism, and the optical element is controlled based on the position information from the magnetic sensor 42b of the autofocus mechanism.

The “closed loop control” means that the AF lens is controlled from the signal of the AF magnetic sensor.
“Open loop control” means that a magnetic field is generated by energizing a VCM (voice coil motor), and a lens connected to the magnet moves due to attraction and repulsion with a magnet provided nearby. Means. The lens stops at a position where the force of attraction / repulsion between the VCM and the magnet and the force of the spring provided to hold the position of the lens are suspended. That is, the lens position is changed by changing the energization amount to the VCM. In order to fix the lens at a desired position, it is necessary to continue energizing the VCM, which increases current consumption. Further, when the lens position is stopped, the elastic vibration of the spring is generated, and it takes time until the vibration converges, resulting in a slow focus speed.

  Further, since the closed loop control does not have a spring for lens positioning, unlike the open loop control, it is not necessary to apply an energization amount sufficient to suspend the force with the spring to the VCM. Further, the closed loop control has no advantage of the positioning spring itself. Therefore, unlike the open loop control, the lens does not become stable until the elastic vibration of the spring is converged.

10 is a block diagram for explaining a third embodiment of the position detection apparatus according to the present invention, and FIG. 11 is a top view of the position detection apparatus according to the third embodiment shown in FIG. That is, it is a diagram in which the relationship between the magnet and the inner and outer sides of the autofocus coil shown in FIG. 4 is reversed, and a configuration diagram in which the autofocus coil is arranged outside the magnet is shown.
The position detection apparatus of the third embodiment is a position detection apparatus having an autofocus mechanism for moving a lens, which is an optical element, along the optical axis direction a.

The first and second autofocus coils 53a and 53b are wound around the optical axis direction a, and the axial direction is provided in parallel with the optical axis direction a.
Any or all of the magnets 51a to 51d are arranged apart from each other around the first and second autofocus coils 53a and 53b in a plan view perpendicular to the optical axis direction a. That is, in FIG. 10, a plurality of magnets 51a to 51d are arranged along the inner periphery of the first autofocus coil 53a and the second autofocus coil 53b.

The magnetic sensor 52a has a magnetosensitive axis parallel to the optical axis direction a, and the magnetosensitive axis is a central axis b in the conductor width d of the current path of the first and second autofocus coils 53a and 53b. The magnetic field of any of the magnets 51a to 51d is detected.
Further, a support unit (not shown) (reference numeral 54 in FIG. 14 (b)) is arranged at a position along the optical axis direction a of the first and second autofocus coils 53a and 53b with the first and second magnetic sensors 52a. The second autofocus coils 53a and 53b are supported.

  The first and second autofocus coils 53a and 53b are preferably arranged in parallel to each other with respect to the optical axis direction a, and the first and second autofocus coils 53a have the same shape. The magnetic sensor 52a is sandwiched between the first autofocus coil 53a and the second autofocus coil 53b, ie, the periphery along the conductor width d of the first autofocus coil 53a and the second autofocus coil 53b. Is arranged.

In addition, any or all of the magnetization directions of the magnets 51a to 51d are perpendicular to the optical axis direction a, and the radial directions of the first and second autofocus coils 53a and 53b from the magnets 51a to 51d or Magnetized in the surface direction.
The first autofocus coil 53a and the second autofocus coil 53b are square coils, and the magnetic sensor 52a is disposed between the center positions of either one of the square coils. Note that the cross-sectional shape of the autofocus coil may be any of a circle, an ellipse, and a rectangle.

Further, the magnetic sensor 52a is sandwiched between the first autofocus coil 53a and the second autofocus coil 53b, and is disposed at the center position in the longitudinal direction and the short direction perpendicular to the magnetizing direction of the magnet. Yes. The magnetic sensor is preferably a Hall element.
A plurality of magnets 51a to 51d are arranged along the inner periphery of the first autofocus coil 53a and the second autofocus coil 53b.
The magnetic sensor 52b is sandwiched between the first autofocus coil 53a and the second autofocus coil 53b, and is disposed between the adjacent magnets 51a and 51c, 51c and 51b, 51b and 51d, and 51d and 51a. ing.

Further, a camera shake correction coil 55 provided in the vicinity of the magnets 51a to 51d, a camera shake correction X-axis detection magnetic sensor 59X driven by the camera shake correction coil 55, and a camera shake correction Y-axis detection magnetic sensor 59Y. And further.
Further, the axial direction of the camera shake correction coil 55 is arranged to be parallel to the optical axis direction a.
Further, closed-loop control is used for the autofocus mechanism, and the optical element is controlled based on position information from the magnetic sensor 52b of the autofocus mechanism. The magnetic sensor is preferably a Hall element.
With such a configuration, the same effect as in FIG. 4 can be obtained if the autofocus coil and the Hall element move in conjunction with the movement of the lens.

In other words, since the autofocus coil and the magnetic sensor are supported by the support portion, the magnetic sensor also moves along with the autofocus coil, and the relative position of the magnet and the magnetic sensor changes. By detecting the position, the position can be detected, thereby enabling closed loop control.
In addition, since the magnetic field generated from the autofocus coil is parallel to the magnetic sensing direction with respect to the magnetic sensor, the magnetic sensor is not easily affected by the leakage magnetic field. Furthermore, linearity is improved by using a magnetic sensor in which the magnetosensitive direction is the optical axis direction with respect to the magnet.

FIG. 12 is a block diagram for explaining a fourth embodiment of the position detection apparatus according to the present invention, and FIG. 13 is a top view of the position detection apparatus according to the fourth embodiment shown in FIG. In addition, the same code | symbol is attached | subjected to the component which has the same function as FIG.
Unlike the arrangement position of the magnetic sensor 52a shown in FIG. 10, the magnetic sensor 52b is sandwiched between the first autofocus coil 53a and the second autofocus coil 53b, and is magnetized with any of the magnets 51a to 51d. It is arranged at a position deviating from the center position in the longitudinal direction and the short direction perpendicular to the direction.

Further, the magnets 41a to 41d shown in FIG. 6 are arranged outside the autofocus coils 43a and 43b, whereas the magnets 51a to 51d shown in FIG. 12 are arranged inside the autofocus coils 53a and 53b. Has been placed.
That is, the condition of the magnetic sensor position shown in FIG. 12 may be any position as long as the magnetic field of the autofocus coil enters parallel to the surface of the magnetic sensor and the necessary linearity can be ensured. Thus, for example, as shown in FIG. 10, the magnetic sensor does not necessarily have to be the center of the magnet, and as shown in FIG. 12, high linearity can be ensured even between the two magnets.

<Specific example 2>
FIGS. 14A and 14B are configuration diagrams for explaining a specific example 2 as the fourth embodiment shown in FIG. 12, and FIG. 14A shows a magnet, an autofocus coil, a magnetic sensor, and an OIS. FIG. 14B is a perspective view in which a holding mechanism for a guide bar and an autofocus coil and a mounting substrate are attached. Components having the same functions as those in FIG. 12 are denoted by the same reference numerals.
That is, FIG. 14A is a diagram in which elements unnecessary for the magnetic circuit such as the substrate, the holding mechanism, and the guide bar are deleted from FIG. 14B.

  As shown in FIG. 12, the magnetic sensor 52b is sandwiched between the first autofocus coil 53a and the second autofocus coil 53b, and has a longitudinal direction perpendicular to the magnetization direction of the magnets 51a to 51d and It is arranged at a position deviating from the center position in the short direction. That is, the magnetic sensor 52b is sandwiched between the first autofocus coil 53a and the second autofocus coil 53b, and is disposed between the adjacent magnets 51c and 51b. The magnetic sensor 52b may be disposed between the magnets 51d and 51a, 51a and 51c, and 51b and 51d.

Further, the support portion 54 as a lens holder has a magnetic sensor 52b and the first and second autofocus coils 53a at positions along the optical axis direction a of the first and second autofocus coils 53a and 53b. , 53b.
In addition, the camera shake correction coil 55 is provided on a flexible printed circuit board (FPCB) 58 and is disposed corresponding to each of the magnets 51a to 51d.

The guide bar 56 is a module in which the first and second autofocus coils 53a and 53b and the magnetic sensor 52b are integrated so that the first and second autofocus coils 53a and 53b do not rotate. It is provided to operate only on the shaft.
Further, the camera shake correction drive unit support portion 57 is provided between the camera shake correction coil 55 and each of the magnets 51 a to 51 d so as to correspond to the flexible printed circuit board (FPCB) 58.
With such a configuration, it is useful to arrange the magnetic sensor at the corner of the actuator in order to reduce the actuator size.

15 (a) to 15 (d) are configuration diagrams provided with the camera shake correction function in the specific example 2 shown in FIG. 14 (a), and FIG. 15 (a) is the same perspective view as FIG. 14 (a). 15 (b) is a top view of FIG. 15 (a), FIG. 15 (c) is a side view of FIG. 15 (a), and FIG. 15 (d) is a side view of FIG. 15 (b). In the figure, reference numeral 59X indicates a camera shake correction magnetic sensor (X-axis detection), and 59Y indicates a camera shake correction magnetic sensor (Y-axis detection).
That is, FIG. 15A is a diagram in which elements unnecessary for the magnetic circuit such as the substrate, the holding mechanism, and the guide bar are deleted from FIG. 14B.

An image stabilization coil 55 provided in the vicinity of the magnets 51a to 51d, an image stabilization magnetic sensor (X-axis detection) 59X and an image stabilization magnetic sensor (Y) fixed on the same substrate as the image stabilization coil 55. Axis detection) 59Y.
Further, the axial direction of the camera shake correction coil 55 is arranged to be parallel to the optical axis direction a. By energizing the camera shake correction coil 55, the guide bar 56, magnets 51a to 51d supported by the camera shake correction drive unit support portion 57, and the support portion 54 as a lens holder are driven in the X axis and the Y axis.
Further, the closed loop control is used for the autofocus mechanism, and the optical element is controlled based on the position information from the magnetic sensor 52b of the autofocus mechanism.

11, 21, 31, 41a to 41d, 51a to 51d Magnets 12, 22, 32, 42a, 42b, 52a, 52b Magnetic sensors 13a, 43a, 53a First autofocus coils 13b, 43b, 53b Second autofocus Coils 23, 33 Autofocus coils 44, 54 Support portions 45, 55 as lens holders Shake correction coils 46, 56 Guide bars 47, 57 Shake correction drive unit support portions 48, 58 Flexible printed circuit board (FPCB)
49X, 59X Camera shake correction magnetic sensor (X-axis detection)
49Y, 59Y Magnetic sensor for camera shake correction (Y-axis detection)
62 Magnet 63Z Z-axis AF coil 64Z Z-axis AF sensor

Claims (14)

In a position detection apparatus having an autofocus mechanism for moving an optical element along an optical axis direction,
A first autofocus coil wound around the optical axis direction;
A magnet disposed in the periphery of the first autofocus coil in a plan view perpendicular to the optical axis direction;
A magnetic sensor whose magnetic axis is parallel to the optical axis direction and detects the magnetic field of the magnet;
The first autofocus coil and the magnetic sensor are supported so that the magnetic sensor is disposed in a region along the optical axis direction of the conductor width of the conductor portion forming the first autofocus coil. A support part;
A position detecting device.   The support portion supports the magnetic sensor and the first autofocus coil so that a magnetic sensitive axis of the magnetic sensor is close to a central axis along the optical axis direction in the conductor width of the conductor portion. The position detection device according to claim 1.   The optical sensor further includes the first autofocus coil and the second autofocus coil, which are arranged in parallel to the first autofocus coil with respect to the optical axis direction, and the magnetic sensor includes the first autofocus coil. The position detection device according to claim 1, wherein the position detection device is disposed between the coil and the second autofocus coil.   The magnetizing direction of the magnet is perpendicular to the optical axis direction, and is magnetized from the magnet in the surface direction of the first and second autofocus coils. The position detection apparatus described in 1.   The magnetic sensor is sandwiched between the first autofocus coil and the second autofocus coil, and is disposed at the center position in the longitudinal direction and the short direction perpendicular to the magnetizing direction of the magnet. The position detection device according to claim 1.   The magnetic sensor is sandwiched between the first autofocus coil and the second autofocus coil and at a position deviated from the center position in the longitudinal direction and the short direction perpendicular to the magnetizing direction of the magnet. The position detection device according to claim 1, wherein the position detection device is disposed.   The position detection device according to claim 1, wherein a plurality of the magnets are arranged along the periphery of the first autofocus coil and the second autofocus coil.   The position detection device according to claim 7, wherein the magnetic sensor is sandwiched between the first autofocus coil and the second autofocus coil, and is disposed between the adjacent magnets.   The position detection device according to claim 7 or 8, wherein the first autofocus coil and the second autofocus coil are disposed inside the plurality of magnets.   The position detection device according to claim 7 or 8, wherein the first autofocus coil and the second autofocus coil are disposed outside the plurality of magnets.   The position detection device according to claim 1, wherein the first autofocus coil and the second autofocus coil have the same shape.   The first autofocus coil and the second autofocus coil are square coils, and the magnetic sensor is disposed between four corners of the square coil. Position detection device.   The position detection device according to claim 1, wherein closed loop control is used for the autofocus mechanism, and the optical element is controlled based on position information from the magnetic sensor of the autofocus mechanism.   The position detection device according to claim 1, wherein the magnetic sensor is a Hall element.

Images